2. Academic Validation
  3. NONO regulates m5C modification and alternative splicing of PTEN mRNAs to drive gastric cancer progression

NONO regulates m5C modification and alternative splicing of PTEN mRNAs to drive gastric cancer progression

  • J Exp Clin Cancer Res. 2025 Mar 4;44(1):81. doi: 10.1186/s13046-024-03260-z.
Gaichao Zhao 1,  Ruochen Liu 1 2,  Lingjun Ge 1,  Dan Qi 1,  Qishu Wu 1,  Zini Lin 1,  Houji Song 1,  Liping Zhong 3,  Hongjuan Cui 4 5 6 7
Affiliations

Affiliations

  • 1 State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400716, China.
  • 2 Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400716, China.
  • 3 State Key Laboratory of Targeting Oncology, Guangxi Medical University, Nanning, 530021, Guangxi, China. zhong_liping@163.com.
  • 4 State Key Laboratory of Resource Insects, Medical Research Institute, Southwest University, Chongqing, 400716, China. hcui@swu.edu.cn.
  • 5 Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing, 400716, China. hcui@swu.edu.cn.
  • 6 Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, 400716, China. hcui@swu.edu.cn.
  • 7 Jinfeng Laboratory, Chongqing, 401329, China. hcui@swu.edu.cn.
PMID: 40033337 DOI: 10.1186/s13046-024-03260-z
Abstract

Background: The effect of m5C modification on oncogene mRNAs has been well studied, while little is known about its influence on mRNAs of tumor suppressor genes (TSGs). Early studies showed PTEN, a key TSG, undergoes alternative splicing (AS) in cancers, however, the underlying regulatory mechanism remains elusive.

Methods: We analyzed tissue microarrays and transcriptomic data derived from gastric Cancer, with an emphasis on RNA splicing and m5C regulators. To unravel the role of NONO in GC, we employed RNA Sequencing, RNA-Bis-Seq, RNA immunoprecipitation, RNA in situ hybridization, and Minigene reporter assay with NONO knockdown cells. The clinical relevance was validated using CDX models and human tissue microarrays.

Results: Analysis of publicly available datasets and immunohistochemistry assay of tissue microarrays containing 40 GC tissues showed NONO was upregulated in GC and contributed to poor prognosis. In vitro and in vivo experiments indicated a positive regulatory role of NONO in terms of cell proliferation, migration, and invasion of GC. Mechanically, NONO interacted directly with PTEN pre-mRNA and recruited the RNA m5C methyltransferase NSUN2 via RNA-recognition motif (RRM) domains, altering the mRNA methylation pattern across PTEN pre-mRNA. The oncogenic role of NONO/NSUN2/PTEN axis in GC progression was further confirmed with pre-clinical experiments and clinical data.

Conclusion: Here, we revealed NONO-regulated AS of PTEN mRNA in an m5C-dependent manner, resulting in the downregulation of PTEN expression in gastric Cancer (GC).This study unveils a novel regulatory mechanism of tumor suppressor gene inactivation mediated by m5C modification and related alternative splicing in Cancer.

Keywords

Alternative splicing; GC; NONO; NSUN2; PTEN; m5C.

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